Pedro Alonso López, a Colombian serial killer, raped and killed more than 300 girls across South America and preyed on young, unsafe girls in Peru. He tempted them to secluded areas or inside empty buildings where he raped them and strangulated them before brutally killing. López was arrested when an attempted kidnap failed and he was trapped by market traders. Confessing to over 300 murders, the police only believed him when a a mass of grave containing his victims. 53 bodies were discovered and he was imprisoned in 1980. Served just 18 years before releasing from a Ecuadorian prison. He was deported to Columbia and was rearrested. In 2002 he was sentenced to life.
3. Jeffrey Dahmer
Jeffrey Dahmer is the scariest serial killers of the United States. In his thirteen years, Dahmer killed 17 men and boys. He murdered, rapes, necrophilia, dismemberment and cannibalism. The police discovered very disturbing things in his apartment. Apparently, while he was doing a horrific sexual act, he drills into the alive heads and skulls of his victims. When they died, he either had sex with the bodies or ate pieces of them. He was arrested in 1994 and was beaten to death by a jail inmate.